A. Field of the Invention
The invention generally concerns the use of semi-conductive polymers that can be used in organic photovoltaic cells.
B. Description of Related Art
Rising energy prices and concerns relating to global warming from burning fossil fuels has led to a search for more cost effective and efficient renewable energy sources. One such source of renewable energy that has been identified is solar energy. The problems associated with converting solar energy into electricity has been, in large part due to the inefficiencies of the energy conversion process. For instance, photovoltaic cells (e.g., solar cells) have been developed that can convert solar energy into usable energy, but the costs associated with doing so have hindered the widespread application of this technology into the marketplace.
In recent years research relating to the use of polymers in the photoactive layers of organic photovoltaic cells has increased. One of the unique aspects of using polymers is that they allow organic electronic devices to be manufactured by cost-effective solution-processing techniques such as spin casting, dip coating or ink jet printing. Solution processing can be carried out cheaper and on a larger scale compared to the evaporative techniques used to make inorganic thin film devices, which rely on vacuum deposition techniques. Many of the polymers that are currently being used suffer from low charge carrier mobility (electrical conduction) and are complicated to synthesize, which increases the ultimate costs of production.